|  | 7.3 | Novell Routing
| 7.3.3 | Get n earest s erver p rotocol
NetWare clients automatically discover available network services because Novell servers and routers announce the services by using SAP broadcasts. One type of SAP advertisement is GNS, which enables a client to quickly locate the nearest server for login. The NetWare client/server interaction begins when the client powers up and runs its client startup programs. These programs use the client's network adapter on the LAN and initiate the connection sequence for the NetWare command shell to use. The connection sequence is a broadcast that comes from a client using SAP. The nearest NetWare file server responds with another SAP; the protocol type is GNS. From that point on, the client can log in to the target server, make a connection, set the packet size, and proceed to use server resources. If a NetWare server is located on the segment, it responds to the client request. The Cisco router does not respond to the GNS request. If there are no NetWare servers on the local network, the Cisco router responds with a server address from its own SAP table. Cisco IOS software allows NetWare clients to be located on LAN segments where there are no servers. When a NetWare client wants to locate a NetWare server, it issues a NetWare GNS request. Cisco routers listen to NetWare traffic, identify eligible servers, and forward the GNS requests specifically to them. By filtering GNS packets, you can explicitly exclude selected servers, providing greater security and flexibility in network design. In responding to GNS requests, Cisco IOS software can also distribute clients evenly among the available servers. For example, assume that Clients A and B both issue GNS requests. The Cisco router sends a GNS response to Client A, telling it to communicate with Server 1, and a GNS response to Client B, telling it to communicate with Server 2. By supporting serverless LAN segments and distributing clients evenly among available servers, Cisco IOS software provides network-based load sharing, improves application availability, and minimizes the need to configure and manage large numbers of local servers, assuming that the servers are identical.